使用sqlite3在android中创建数据库的问题

Question

我使用sqlite3使用SQLiteOpenHelper类创建数据库但无法创建数据库。使用的代码如下：

public class ABCHelper extends SQLiteOpenHelper {

public static final String TABLE_COMMENTS = "comments";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_COMMENT = "comment2";

private static final String DATABASE_NAME = "commments.db";
private static final int DATABASE_VERSION = 1;

// Database creation sql statement
private static final String DATABASE_CREATE = "create table "
        + TABLE_COMMENTS + "(" + COLUMN_ID
        + " integer primary key autoincrement, " + COLUMN_COMMENT
        + " text not null);";

public ABCHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase database) {
    database.execSQL(DATABASE_CREATE);
    Log.d("EventsData", "onCreate: " + DATABASE_CREATE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    Log.w(ABCHelper.class.getName(), "Upgrading database from version "
            + oldVersion + " to " + newVersion
            + ", which will destroy all old data");
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_COMMENTS);
    onCreate(db);
}
}

Answer 1

如果将“text”更改为VARCHAR（255）怎么办？